Some time ago I worked in a research group investigating the effects of vitamin A on embryonic development in mice. Now I searched in my library for the information you require. Unfortunately, there were reports in the literature of some clinical cases of human embryos exposed to retinoic acid (vitamin A) compounds as early as the first two days after conception which had severe abnormalities of some brain structures. Although, these are just single cases and I haven't found any statistics, I guess nobody can guarantee the outcome of such a pregnancy.Was it one of retinoic acid drugs that your friend took?I am very sorry to have nothing positive to say to your friend.